Add visit placement on care units and beds.

Patients can be admitted, transferred, and discharged from unit/bed stays with occupancy sync, so MAR and ward boards have inpatient context.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Models/CareUnit.php

@@ -53,6 +53,16 @@ class CareUnit extends Model
         return $this->hasMany(StaffAssignment::class, 'care_unit_id');
     }
 
+    public function visits(): HasMany
+    {
+        return $this->hasMany(Visit::class, 'care_unit_id');
+    }
+
+    public function activeStays(): HasMany
+    {
+        return $this->hasMany(BedStay::class, 'care_unit_id')->where('status', BedStay::STATUS_ACTIVE);
+    }
+
     public function supportsBeds(): bool
     {
         return $this->kind === 'inpatient';